Monday 2 July 2018

Four Kinds Of Timelines

In Poul Anderson's works, "time travel" occurs in diverse timelines where, e.g.:

(i) many space-time vehicles continually appear from, or disappear into, actual or potential pasts or futures;

(ii) a few space-time vehicles, expending immense amounts of energy, move across Earth's surface while also moving backwards or forwards in time;

(iii) a few mutants move backwards or forwards in time without vehicles;

(iv) two warring groups move backwards or forwards along corridors that have been rotated onto the temporal axis.

It is as if the author has systematically considered every possibility:

(i) many vehicles;
(ii) few vehicles;
(iii) no vehicles;
(iv) corridors instead of vehicles.

In (i), the vehicles do not move but merely disappear and reappear.
In (ii), the vehicles and their occupants, described as "moving," really only age/endure/durate at a reduced rate.
In (iii), the mutants do likewise.
In (iv), the corridor-users really do move along the temporal dimension of the external universe.

In (i), time travelers can "change the past"/violate causality.
In (iii) and (iv), they cannot.
(ii) is ambiguous. The dying futurian, Sahir, asks Duncan Reid to contact other time travelers who will arrive a year hence and says:

"'They'll come through time, to this day, bring help, surely -'"
-Poul Anderson, The Dancer From Atlantis (London, 1977), Chapter Four, p. 33.

Does he think that there might be a divergent timeline in which he is rescued?

6 comments:

Sean M. Brooks said...

Kaor, Paul!

Just a small correction, about your point (i). In Anderson's Time Patrol stories we do sometimes see Patrol time cycles being used like planes or flying machines (esp. in "Delenda Est").

And I think Sahir was hoping that rescuers from his future would come at that very moment just in time to save his life.

Sean

paulshackley2017@gmail.com said...

Sean,
Yes. I meant that the timecycles do not really move through time.
Paul.

Sean M. Brooks said...

Kaor, Paul!

But in Anderson's Time Patrol stories a time cycle does "go" from one point in time to a different "temporal" location. That is a kind of moving thru time.

Sean

paulshackley2017@gmail.com said...

Sean,
OK but not literal motion traversing the space-time between the points.
Paul.

Sean M. Brooks said...

Kaor, Paul!

Granted. Patrol agents using time cycles will pop into existence at the same location, but simply at different times.

Sean

paulshackley2017@gmail.com said...

Sean,
Or jump to different space-time coordinates.
Paul.